The explosive growth of both portable and desktop touch screen devices has meant a heightened need to keep such surfaces clean. Use of a touch screen device, by name, involves touching by a user's fingers. Any oils, moisture, or various other materials found on one's fingertips can be transferred to the surface of a touch screen device. Overtime, these materials can accumulate and deleteriously affect the functionality, viewability, and general appearance of the device. Existing coating compositions and/or methods have proved unsatisfactory in terms of cost, efficient use of materials, longevity and/or the ability to resist abrasion, water, cleaning agents and lipids.
Glass hardening has been used to strengthen touch screen substrates against breakage, scratching and abrasion. Conventional hardening techniques, however, result in glass surfaces having reduced population densities of hydroxyl groups that could be used for bonding with an organo-metallic and/or silane coating material. Treating substrates to increase hydroxyl group population densities destroys or removes surface-compression elements, such as large atoms or ions, and strength gains from pre-hardening procedures are lost. Accordingly, there exists a need for better pre-hardened glass substrates for touch screens, and for coating methods and compositions for forming touch screen surfaces.